Vinification Flashcards
1
Q
EU definition of “wine”
A
The product obtained exclusively from the total or partial alcoholic fermentation of fresh grapes, whether or not crushed, or of grape must
2
Q
Grape maturity
A
One of the most decisive factors in determining wine quality and style Physiological changes - phenolics & taste Biochemical changes - sugars & acids
3
Q
Key questions for harvesting
A
When
Forecasting
Preparing
How (manual vs machine)
4
Q
Harvest date
A
Grape ripeness
- sugar
- acid
- health
- phenolic ripeness
Agrochemicals (fungicides, insecticides, herbicides, pesticides, etc)
- withholding period
- fermentation and health problems
e.g. sulphur –> hydrogen sulphide
copper –> brown haze, toxic copper salts in wine
Weather
- rain –> dilution, grape swelling and bursting
- hail
Availability of resources (human and mechanical)
Legal restrictions
5
Q
Havesting - Getting ready
A
Estimating the crop (sufficient tank space)
Checking & cleaning equipment and machinery
Tanks clean and ready for use
Oenological products (yeasts, sulphur, enzymes, etc)
6
Q
Havesting - Machine vs Hand
A
Factors to consider
- quality
- speed
- economics
- feasibility
Machine
- speed, grapes at peak; cheaper labour costs; cool night
- damage, oxidation, no selection, cost of machinery, flat land, trellis system (no bush nor pergolas)
Manual
- less damage, more selectivity, slopes, less $ for equipment
- high labour costs (10X machine), slower
- for sparkling wine, carbonic maceration (whole bunches); Tokaji, Beerenauslese, Trockenbeerenauslese (selection of grapes); required by law
7
Q
Harvesting - Transport & Reception
A
Use shallow picking containers
Less transfer between containers
Less dumping heights
Refrigerated trucks
Minimize delay before processing
Oxidation
- browning, loss of aroma
- CO2/nitrogen blanket; potassium metabisulphite; harvest at night; min delay
Microbial growth
- eliminate rotten grapes; clean equipment; berry integrity; min delay
Contamination
- rain
- leaves & stalks
- MOG (material other than grape)
- soil
8
Q
Key questions for grape processing
A
Sorting
De-stemming
Crushing
Type of press
Amount of SO2
Must treatments
9
Q
Sorting in French
A
Triage
10
Q
De-stemming
A
Tannin control and ease of processing
Egrappoir = de-stemming machine
Most grapes are de-stemmed
Not for sparkling wines and carbonic maceration
Not required for machine harvested grapes
Pros
- prevent release of phenolics, herbaceous flavours, MOG
- more efficient pressing
- remove water and potassium (absorb colour and alcohol)
Cons
- whites: slower pressing and drainage (not for fine wines)
- reds: compaction of pomace cap; tannins and colour
11
Q
Crushing
A
Release free-run juice
Reduce the solid parts of the grape to the correct condition for fermentation and maceration Increase extraction of tannin and colour
Careful not to damage grape seeds
Not to crush for semi-carbonic maceration (Spain, Beaujolais, Languedoc-Roussillon for Carignan and Grenache)
Fouloir = crusher
Equipment
- foot or de-stem/crush
- heat exchanger
- SO2 to reduce oxidation and prevent microbial spoilage
- use of pectolytic enzymes to release more juice
12
Q
Pressing
A
Use of minimum pressure
Done at grape reception for whites; after fermentation for reds
70% of the total weight
Skin contact for aromatic whites (Sauvignon Blanc, Semillon, Muscat, Riesling, Gewuztraminer, Viognier)
- 5-10 C
- few to 24 hours -
- pectolytic enzyme
Finest aromatic wines
- very gentle whole-bunch pressing
- no skin contact
13
Q
Types of press
A
Vertical screw press (basket press)
- simple and easy; clear must or wine
- slow, labour intensive; extraction of bitter phenolics; oxidation
- high-class wineries; champagne
Horizontal screw press (e.g. Vaslin)
- more efficeint in terms of time and labour; simple; can be automated; prevent oxidation with inert gases
- rather coarse juice; extraction of bitter phenolics; high pressure reduces quality
Pneumatic press (e.v. Willmes)
- low pressure; good extraction; less bitter phenolics; high quality juice
- very slow
Tank press (pneumatic press with inert gas)
- no oxygen contact; high quality juice
- very slow; costly
Continuous screw press
- high throughput; less labour-intensive and time consuming
- poor quality; bitter phenolics
14
Q
Must Treatments
A
Before fermentation
- SO2
- Clarification
- Enrichment or Chaptalisation
- Must concentration
- De-acidification
- Acidification
- Tannin
- Bentonite
- Flavour and colour enhancing enzymes
- Oxygen
15
Q
SO2 in winemaking
A
Prevent oxidation and premature fermentation
Kill bacteria (for whites)
Stun weaker yeasts
Improve extraction of polyphenols from skins (for reds)
Four properties:
- Antiseptic - kills microorganisms (acetobacter/wild yeasts)
- Antioxidant - binds with oxygen
- Antioxidasic - denatures oxidasic enzymes
- Combines with acetaldehyde (by-product of oxidation)
16
Q
Four forms of SO2
A
Potassium metabisulphate powder
Compressed and liquidified SO2 gas
SO2 in solution (5%)
Burning sulphur tablets or candles
17
Q
SO2 levels
A
Based on style of wine, health of grapes, pH
Lower for organic wines
Recommended
- White: 60-100 mg/l
- Red: 10-60 mg/l
Limits -
- Dry white: 200 mg/l
- Dry red: 150 mg/l (red wines contain natural anti-oxidants)
- Off-dry white (5g/l sugar): 250 mg/l
- BA/TBA/Sauternes: 390 mg/l (binding power of sugars)
18
Q
Free, bound and total SO2
A
Free - active, protective, molecular SO2 & sulphurous acid
Bound - combined with sugars, aldehydes, ketones, inactive
Total - free + bound
19
Q
Pre-fermentation clarification
A
Remove solid particles
Produce cleaner flavours, more finesse, less bitter
Depend on
- state of the harvest
- grape processing method
- wine style required (little for full-bodied, complex wines; more for delicate and highly aromatic wines)
20
Q
Clarification methods
A
Cold settling (common)
- debourbage
- by gravity
- 12 to 24 hours
- cool temperature (5-10 C)
- clear must racked off the sediment (lees)
- pectolytic enzymes and SO2
Centrifugation
- high level of clarity
- harsh, high risk of oxidation, expensive
- large wineries
Diatomaceous earth filtration
- for aromatic grapes
- can strip the must of nutrients for fermentation
Flotation
- bubbling small amounts of N, CO2 or air
- catching and floating solid particles
- skimmed off by a rotary suction device
- large wineries or cooperatives
21
Q
Enrichment
A
Adding sugar to increase potential alcohol
No effect on wine sweetness
Permitted in cool regions
Unusually cool summer or early harvest in warm regions
Not allowed in Italy/Spain
22
Q
Forms of sugar for enrichment
A
Sucrose (beet sugar) or cane sugar - chaptalisation
RCGM (rectified concentrated grape must) - enrichment
1 kg of sugar increase vol of wine by 0.63 l
White: 1% abv require 17 g/l sugar
Red: 1% abv require 19 g/l sugar (evaporation due to higher fermentation temp & pumping over)
23
Q
Must concentration techniques
A
Vacuum evaporation
- water evaporates at low temperature of 20 C
- loss of aromas, hence use of chilled aroma trap
Reverse osmosis
- high pressure applied to must against a membrane filter
- no loss of aromas
- also used to remove alcohol and volatile acidity
Cryoextraction
- chill grapes to remove water in from of ice
- no loss of aromas
24
Q
EU Rules on enrichment
A
Wine must be > 8.5% alcohol
Enriched wine < 11.5% (white) or 12% (red and rose)
Concentration not to increase alcohol by > 2% or reduce vol by 20% (whichever is lower)
Only one enrichment method and no blending of differently enriched wines
25
Potential alcohol
Alcohol level that would result if all sugars are fermented
26
Actual alcohol
Actual alcohol level after fermentation
27
Residual sugar
Unfermented sugars (natural or added) left in the wine expressed as g/l or %
28
Total alcohol
Actual alcohol + potential alcohol from residual sugar
29
Natural alcohol
Total alcohol in an un-enriched must or wine
30
De-acidification
Tartaric acid cannot be reduced by \> 1 g/l
Not permitted in warmest regions - CIII(b)
Increase pH, therefore risk of microbial infection and decrease effectiveness of SO2
31
De-acidification methods
Tartaric only
* potassium bicarbonate (potassium tartrate crystals)
* calcium carbonate (leaves high level of calcium tartrate)
Malic only
* malolactic fermentation
Both tartaric and malic
* Double-salt de-acidification
* Acidex (specifially prepared calcium carbonate with small amount of calcium tartrate-malate)
* calcium tartrate-malate crystals
32
Acidification
"buffering" effects
logorithmic pH scale
* more acid to alter pH from 3.2 to 3.0 than from 3.8 to 3.6
CII and CIII zones
Not in Rhone
Tartaric acid for acidification
* 1.5 g/l in must; 2.5 g/l in wine
Citric acid
* 1 g/l in must
* never added before fermentation
* metabolised by yeast and bacteria to form acetic acid
33
Tannin
Added before fermentation
Protection from oxidation
Stablilize colour
Improve mouth feel
34
Bentonite
Fining agent in form of clay
Remove proteins
Non-selective and remove flavour compounds
35
Flavour and colour enhancing enzymes
Aid juice extraction
Optimise extraction of aroma precursors
Improve colour extraction
Increase efficiency of settling
Developed from fungi
Added at crushing
36
Use of oxygen in winemaking
Hyperoxidation
Development of yeasts at start of fermentation
Revitalization of yeast
Micro-oxygenation of harsh polyphenols in barrels
Anaerobic maturation after bottling (not for screwcaps)
Add complexity and character in anaerobically made wines
37
Oxidases
Laccase
* grey rot
* SO2 resistant
* pasteurisation (heating must to 65-70 C)
Tyrosinase
* controlled by SO2 Copper and iron
38
Reductive (anaerobic) handling
Minimize exposure to oxygen
SO2
Low temperatures
Inert gases used to flush out presses, pipes, vats
Reductive taint - sulphur dioxide becomes hydrogen sulphide
39
Oxidative (Aerobic) handling
Minimal use of SO2
Controlled exposure to oxygen
Develop complex flavours and aromas
Enzymatic oxidation of phenolics is encouraged
Form insoluble polymers removed by clarification
More stable wine
Production of oloroso Sherry, tawny Port, vin jaune from the Jura, some Tokaji
40
Hyperoxidation
Bubbling air through the juice
Colour stabilisation in white wines
Can decrease aromalics (e.g. Sauvignon Blanc)
41
Effects of excessive oxygen
Acetaldehyde (ethanal) --\> flat sherry-like flavour
Bitter-tasting components from oxidation of phenolics
Spoilage bacteria, e.g. acetic bacteria
42
Ascorbic acid
Vitamin C
Antioxidant
No antiseptic effect
Used without SO2 --\> hydrogen peroxide (bleaching agent)
43
Alcoholic fermentation
Glucose/fructose + yeasts --\> ethanol + CO2 + energy
* 180 g sugar --\> 92 g alcohol + 88 g CO2
Saccharomyces yeast
* 16-18 g/l sugar needed to produce 1% abv (8 g/l)
Glucose
* dominant early in ripening process
* yeast prefer glucose
Frutose
* dominant in very ripe grapes
* late harvest or botrytis-affected grapes
* difficult to ferment fructose-rich grape must to dry wine
44
Rate of fermentation
Concentration of sugars
Availability of oxygen
Temperature
Type and quantity of yeasts
Nutrient content of the must
SO2
45
Fermentation ceases
All sugar consumed
Alcohol reaches 15% killing yeasts
Increasing pressure of CO2 to 7 atmospheres
Chilling to low temperature (5 C)
SO2
Pasteurisation (80 C for a few second)
Removing yeasts (filtration, centrifuge)
Fortification with spirit
46
By-products of fermentation
Glycerol (Glycerine) - smoothness and weight of wine
Acetaldehyde
Ethyl acetate (nail polish)
Aroma esters
Fusel oils, e.g. methanol
47
Fermentation vessels
Stainless steel tanks
* easy to clean and maintain
* allow temperature control
* rotofermenters
Wooden fermentation vessels
* piece (228 liters) in Burgundy
* barrique (225 litres) in Bordeaux, New World
* open top wooden vats - 1000-5000 litres
* wood retains heat well, need temp control
* difficult to keep clean
* chestnut, cherry, acacia & walnut
Cement tanks
* lined with glass or epoxy
* cheap
* easy to clean and maintain
* no oxygen exchange
* simple temp control
48
Uninoculated fermentations
Started by indigenous yeasts
* Kloeckera/Hanseniaspora
* Candida
* Metschnikowia
Around 4% alcohol
* Saccharomyces takes over
* Saccharomyces cerevisiae
Pros: complex wine
Cons: off-flavours, oxidation, microbiological spoilage
Pied de curve - starter culture
49
Inoculated fermentation
Commercially available active dry yeast
* different strains of Saccharomyces cerevisiae
* higher tolerance of SO2
Pros
* active fermentation onset
* handle highly clarified juice
* fermentation rate more even and easy to control
* no off-flavours or aromas
* efficient conversion of sugar to alcohol
* decreased risk of stuck fermentations
* low volatile acidity (acetic acid) production
Attributes
* tolerance to higher sugar levels (Lalvin Rhone 2226)
* higher glycerol production levels (Maurivin Cru-Blanc)
* efficent extraction of phenolics and enhancement of tannin structure for high quality reds (Lalvin Rhone 2323)
* low temperature tolerant for very fruity whites (R2)
* low foaming (champagne yeasts, e.g. Premier Cuvee for secondary fermentation in bottle)
* Sauvignon Blanc yeasts for aroma/thiol fixing (Lalvin K1V-1116)
50
Monitoring and controlling fermentation
Density
* measures sugar (not alcohol)
* Baume (France): relative density
* Brix or Balling (Australia, NZ, US): hydrometer measurement
* Oechsle (Germany, Switzerland): hydrometer scale
* Babo (Italy), same as KMW (Austria)
Temperature
* controls the rate of fermentation
* chill white grapes/must in warm climates
* fermentation releases heat
Aeration
* yeast needs oxygen
* reds: pumping over (remontage) or punching down (pigeage)
Finishing the fermentation
* density drops below 1
* 2 g/l of unfermentable sugars in dry wines
51
Temperature in fermentation
Optimum fermentation temperature range
* whites: 10 - 18 C
* reds: 20 - 32 C
Excessively high temperature
* oxidation, microbiological spoilage and instability
* loss of aroma and flavour compounds, alcohol
* slow or stuck fermentation (above 35 - 38 C)
Excessively low temperature
* retention of isoamyl acetate (banana/pear) in whites
* poor extraction of colour and tannins in reds - sluggish fermentation
* high levels of ethyl acetate and volatile aroma
52
Options for finishing the fermentation
Aromatic dry white wines
* chill the new wine
* add SO2 (40-100 mg/l)
* remove lees (settling or fining agent)
* rack clean wine and bottle
Full-bodied Chardonnay
* fermented in oak barrels
* extended lees contact, with lees stirring
* MLF
* after MLF, suphited and left to mature in oak
Off-dry white wines
* stop fermentation before dryness
* chilled (\< 5 C)
* racked and filtered to remove yeasts
Sweet fortified wines (Port/vins doux naturels)
* add alcohol to \> 15% abv
Red wines
* maceration to extract tannins and pigments
* New World: fermentation completed in barrels, then MLF
53
Fermentation problems
Stuck fermentations
Yeast nutrient issues
Hydrogen sulphide formation
Carbon dioxide poisoning
54
Stuck fermentation results
Results in
* hydrogen sulphide (VA)
* microbial spoilage
* residual sugar
Caused by
* too hot (\> 35 C) or too cold
* nutrients depleted
* alcohol level (uninoculated fermentation)
Prevented by
* adequate aeration at onset of fermentation
* 100 - 150 mg/l di-ammonium phosphate (DAP)
* 0.5 mg/l thiamine (vitamin B)
* temperature control
"kick-start"
* adjust temperature
* add DAP and thiamine
* re-inoculate with Saccharomyces Bayanus
55
Yeast nutrient issues
Low yeast nutrients in rotten fruit and clarifed must
Add DAP (200 mg/l) and thiamine (1.0 mg/l)
Ammonium sulphate liberates ammonium and SO2
56
Hydrogen sulphide formation
Yeasts deprived of nitrogren (ammmonium)
Break down amino acids to release H2S
Rotten eggs
57
Carbon dioxide poisoning
Colourless, odourless, potentially lethal
Heavier than oxygen
Good ventilation required
Measure oxygen using a meter
58
White winemaking
Grapes pressed before fermentation
Good quality whites
* healthy, ripe grapes
* careful and quick processing
* protection from oxidation
Key decisions
* whole bunch press or de-stem and crush before pressing
* de-acidify, acidify, increase sugar levels
* skin contact (maceration pelliculaire) or press immediately
* clarify must before fermentation
* inoculate
* fermentation vessel
* fermentation temperature (14 - 20 C)
* lees contact
* MLF (No SO2, 16 - 18 C)
* oak
* maturation prior to bottling
59
Fermentation temperature for whites
Optimum 14 - 20 C
* fruit preservation
* \> 20 C reduce esters and increase alcohol
Aromatic whites
* 11 - 15 C to retain fruit esters
* 10 - 13 C to retain volatile esters but produce intense smelling esters (isoamyl acetate)
Afte**r** fermentation, lower temp to 12 C for yeast settling
60
Lees contact
Protect wine from oxidation
Add texture
Autolysis of yeast in lees
Muscadet
Reduction problems
* H2S --\> onion-like mercaptans, difficult to remove
* oxygen by lees stirring or wine racking
* pass through copper pipe or add copper sulphate
Lees stirring (battonage)
* wine in barrique (Chardonnay)
* barrel stackers with rollers to avoid excess oxygen
* bubbling gas in tank
61
Rose winemaking
Drawing-off method
* saignee or bleeding
* de-stemmed, crushed and sulphited grapes
* 6 - 48 hours of skin contact
* cooler temp to retain fruit aromatics and freshness
* higher temp for more colouring
* fermented at 15 - 20 C
* no MLF to retain fresh natural acidity
* clarified, stabilised and bottled young
* Anjou, Bordeaux Clairet, Cotes de Provence
Direct pressing
* freshly harvested red grapes
* not to extract too much tannin
* pale pink
* Cotes de Provence, Languedoc
Blending
* Rose Champagne, New World Roses
* not permitted in EU for still roses
62
Definition of "red wine"
A macerated wine.
Extraction of solids from grape cluster (specifically from skins, seeds and possibly stems) accompanies the alcoholic fermentation of the juice.
63
Red winemaking
Skin contact during the alcohol phase and colour of the grape; extraction of phenolic compounds (polyphenolics or polyphenols); pressing after fermentation
5 main steps
* pre-fermentation processing
* alcoholic fermentation
* draining and pressing
* MLF
* maturation
64
Two main types of phenolic compounds
Non-flavonoids
* simple phenolics
* benzoic and cinnamic acids
Flavonoids
* catechins (tannin)
* resveratrol
* anthocyanins (red pigments in skin cells)
* tannin can react with anthocyanins to fix colour
* pigmented tannins polymerise with age and precipitate out
65
Three factors of phenolic extraction
Temperature of fermentation
DAP management
Duration of skin contact
66
Pre-fermentation processing
De-stemming and crushing (not for carbonic maceration)
Fill vessel to \< 80% capacity 20 - 80 mg/l SO2 (wild yeasts, bacteria, oxidative enzymes)
Must adjustment (acidification, enrichment)
Pre-ferment maceration (or "cold soak") to extract aromas
* Cooled to 4 - 15 C and kept for 3 - 7 days (80-100 mg/l SO2)
67
Fermentation temperature for reds
20 - 32 C
Higher temp increase breakdown of skin cells and level of dissolution of phenolics
Moderate temp (25 C)
* good colour extraction
* preservation of primary fruit aromas
* minimal to moderate tannin extraction
Thermovinification
* heating grape to 45 C
* rather coarse wines with "burnt" aromas
68
Cap management
Pomace cap
Methods
* pumping-over (remontage)
* punching down (pigeage)
* rackand return (delestage)
* submerged cap
* rotovinification
* autovinification
69
Pumping-over
Remontage
with or without aeration
pump, hose, fixed spray head
done 1-3 times a day
Benefits
* simple
* good extraction
* tank of wine becomes homogenised
* aeration prevents reduction, aids yeasts
* prevents cap from drying out
Wines
* Cabernet Sauvignon, Merlot
* medium to high quality
* rich, full-bodied structure
* no vegetal or bitter characters
70
Punching down
Pigeage
Manual (paddle)
Automatic (stainless steel cone attached to a hydraulic piston)
Done 1-3 times a day
Benefits
* gentle extraction
* less harsh or bitter compounds
* good disperson of temperature
* avoid bacterial spoilage on surface of cap
Disadvantages
* labour intensive if done manually
* Merlot and Cabernet Sauvignon more rustic in flavour
Wines
* Pinot Noir and premium Syrah
71
Rack and return
Delestage
Tank is drained into another tank, then pumped back over the cap
Done once per day or twice during fermentation
* after initial peak of temp
* middle of fermentation
Benefits
* complete mixing and breaking up of cap
* good aeration
* extraction of phenolics
* seeds can be removed
Disadvantages
* too extractive
72
Submerged cap method
Fermenting fluid filled to over head boards/perforated screen that trap pomace beneath
Constant contact
Benefits
* good extraction
* no risk of pomace cap drying out and VA
Disadvantages
* extraction can be difficult as skins are compressed
73
Rotovinification
Rotofermenter
* horizontal cylindrical fermentation vessel
* motor
Benefits
* fast
* thorough mixing
* good extraction
* automatic and computer-controlled
* pomace kept wet
Disadvantages
* expensive
* robust supporting framework
* reduction problems
* over extraction
Wines
* inexpensive, bulk reds
* premium Barolo
74
Autovinification
Autovinifier, or Algerian Ducellier system
* extended version of pumping-over
* sealed vats
* CO2 pumps must into top reservoir
* cascades back into lower chamber
Benefits
* no external power
* fully automated
* good extraction of colour and tannins
Disadvantages
* difficult to control rate of extraction
Wines
* red Port
* light, good quality wine in North Africa
75
Fermentation management of reds
Complexity of maceration dynamics
Monitor density and temp
Control of temp
Control of aeration
Pumpovers and/or cap punching
Skin contact time (post-ferementation maceration)
76
Duration of skin contact
Extraction enhanced by
* higher temp
* increase in alcohol
Extent of phenolic extraction
* avoid extraction from poor quality grapes
* shorter (around 8 days) for light, easy, early-drinking reds
* longer (3 weeks) for full-bodied reds
* extended (\> 1 months) for high quality vintages
Pectolytic enzymes to increase extraction
Anthocyannis extracted first (temp)
Tannin extracted by higher temp and alcohol
77
Draining and pressing
Free-run wine and press wine
Fining of press wine
Residual sugar in press wine to ferment out
78
Maturation
Lees contact
* reducing properties
* fuller, smoother wines
* mannoproteins released by lees autolysis
* inhibit tartrate crystalization
* bind with tannins to reduce astringency
79
Malolactic fermentation (MLF)
Conversion of malic acid in a wine to lactic acid through the action of naturally-occurring or added bacteria
3 species of lactic acid bacteria
* Lactobacillus
* Leuconostoc
* Pediococcus
Traditionally in tank
Today, commonly in barrel for better oak integration
Biologically more stable wine
Softer, rounder acidity
* malic is sharp (unripe apples)
* lactic is softer (milk)
By-products
* diacetyl (buttery richness)
* higher VA
80
Conditions for MLF
pH between 3.3 - 3.5
Temp between 18 - 25 C
\< 50 mg/l total SO2
Certain amount of nutrients
81
Preventing MLF
Clarify (remove nutrients and bacteria)
SO2 addition after primary fermentation
Low storage temp (\< 12 C) pH below 3.1
Clean containers
Sterile filtration & bottling
82
Encouraging MLF
Keep wine in lees
Low levels of SO2
Warm temp (18 - 22 C)
pH above 3.3
Add Leuconostoc oenos (freeze-dried)
83
Monitoring MLF
CO2
Reduction of malic acid
Paper chromatography
Enzymatic analysis
84
Effects of MLF
Deacidification
* cool climates
* incomplete ripening
Stability
* consuming bacteria nutrients
* useful in reds as lack of protection of added SO2
Loss of primary fruit aromas
* detrimental to aromatic whites
Addition of aromatic compounds e.g. diacetyl
* spoil fruit aromas of Riesling or Sauvignon Blanc
Increase VA
* breakdownof citric acid
Spoilage if lactic acid bacteria not controlled
* SO2, low pH, equipment hygiene
Should never occur in the bottle
85
Carbonic maceration
Fermentation within berries; no yeast; anaerobic respiration of grapes converts sugars to ethanol
Whole bunch
Blanket with CO2
Intercellular fermentation
2% abv and aromatic compounds
Decrease in malic acid, increase in pH
1-3 weeks
Aromas of bananas, kirsch, cherry, plum
86
Semi-carbonic maceration
Beaujolais
Comibination of extra- and intracellular fermentation
No CO2 blanket
Vat filled with grape bunches
Fermentation of crushed bunches at bottom release CO2
Intercellular fermentation of upper layer bunches
Deeply coloured, fruity wines with soft tannins
87
Thermovinification
Heat to 60 - 80 C for 20 - 30 minutes then cool to fermentation temp
Max colour extraction
"Time saver"
Destroy damaging oxidative enzymes in rotten grapes
Pectolytic enzymes and aromas destroyed
Not for premium reds
88
Flash expansion
Flash detente
Pre-heat grapes to 65 - 90 C and place in vacuum
Grapes cooled immediately to 30 - 35 C
Rapid release of anthocyanins and tannins
Juice drained off
89
Sparkling winemaking
Bottle fermented
Traditional Method (methode champenoise)
Transfer Method
Tank Method (cuve close or Charmat)
Carbonation (Pompe bicyclette)
Asti Method & Methode Ancestrale
90
Fortified Winemaking
Types
* Port, Sherry, Madeira
* Muscat in Australia, S France, Greece, Italy
* Vin de Constance (S Africa)
* Malaga (S Spain)
* Mavrodaphne (Greece)
* Commandaria (Cyprus)
Methods
* fortified during fermentation
* fortified after fermentation
91
Fortification during fermentation
Vins doux naturels
* Muscat, Grenache (S France)
* at 5% abv, add high-strength grape spirit (95% abv)
* 15 - 18% abv
Port
* maceration in granite troughts (lagares)
* fermentation at high temp (\> 30 C)
* drain wine at 6 - 9% abv
* 1 part of spirit (77 - 79% abv) to 4 parts of wine
* 8 - 19% abv
Maturation -
* 550 litre "pipe"
Port quality
* base wine
* single vintage or blend
* time in cask - filtered?
Styles
* Ruby Port (\< 3 yrs)
* Tawny Port (longer oxidative time)
* Late Bottled Vintage Port (4-6 yrs)
* Vintage (2-3 yrs)
92
Fortification after fermentation
Sherry
* Town of Jerez
* Palamino, Pedro Ximenez
* 70% free run for Finos, next 20% for Oloroso
* acidified with tartaric acid
* 600 litre oak butts
* uninoculated fermentation (25 - 30 C)
* dry wine, low in alcohol (11 - 11.5%)
* Finos/flor (14.5 - 15.5%) (biologically aged)
* Oloroso (18%) (oxidatively aged)
* Amontillado (aged both biologically an oxidatively)
93
Solera system
Criadera (row)
* simple solera: 3 - 4 criaderas
* complex solera: 14 criaderas
* bottom row called Solera
Fractional blending
* no more than 1/3 of contents drawn
* complex wines
* replenish nutrients for flor
Finos: 3 - 5 yrs
Amontillados/Olorosos: 5-10 yrs
Sweetened prior to bottling
* Pedro Ximenez (Cream Sherries and Sweet Orlorosos)
* concentrated grape juice (Pale Cream Sherries)
Membrane-filtered for Finos and Manzanilla (salty)
94
Sweet wines
3 main methods
* interrupting the fermentation
* adding a sweet component
* concentrating the natural sugars
95
Interrupting the fermentation
Fortification
* Vins doux naturels e.g. Muscat de Beaumes de Venise
* Moscatel de Valencia
* Liqueur Muscats e.g. Rutherglen Muscat
Add SO2 and lower temp
96
Adding a sweetening component
RCGM
Sussreserve (unfermented grape juice)
* German QbA wines
* Rheingau, Rheinhessen, Mosel
97
Concentration of sugars
Drying, e.g. on straw mats
* passerillage -
* Amarone, Vin Santo (Italy, Santorini), PX Sherry (Spain)
Freezing
* Icewine/Eiswein Noble rot
* botrytis cinerea -
* Riesling, Semillon, Chenin Blanc
* Sauternes, Monbazillac in France; Tokaji in Hungary; Beerenauslese and Trokenbeerenauslese in Germany and Austria; botrytis Semillon in Australia
98
Sparkling winemaking
* Traditional Method (methode champenoise)
Bottle fermented
Traditional Method (methode champenoise)
* produce dry base wine
* no SO2 added at end of fermentation
* add liqueur de tirage and yeast
* bottled and sealed (cork or crown seal) - secondary fermentation to increase 1.2 - 1.3% abv
* autolysis of yeasts to add complexity -
* riddled by hand or automatic ridding machines (remuage)
* disgorgement
* add liqueur d'expedition
* sealed by cork and wire cage (muselet)
* further aging
* packing and distribution
* Champagne, Cava, premium sparkling wines
* complex wines, bready, biscuit flavours
99
Sparkling winemaking
* Transfer Method
Bottle fermented
Transfer Method
* fermented wine emptied into pressurized tank
* cooled to -5 C
* add dosage (sweetening wine)
* filter to bottle
* slight loss of quality
* mid-market New World sparkling wines
100
Sparkling winemaking
* Tank Method
Bottle fermented
Tank Method (cuve close or Charmat)
* secondary fermentation in sealed pressurised tank
* lees contact
* sweetened, filtered and bottled under pressure
* lower production costs
* German Sekt and Prosecco
* coarser and broader bubbles
101
Sparkling winemaking
* Carbonation
Bottle fermented
Carbonation (Pompe bicyclette)
* chill wine
* bubble carbon dioxide into it
* very inferior method
102
Sparkling winemaking
* Asti Method
Bottle fermented
Asti Method & Methode Ancestrale
* Moscato
* must pumped into a pressure vessel and yeast added
* CO2 allowed to escape to atmosphere
* 5% abv: valves closed to trap CO2
* 6-9% abv and 60-100 g/l sugar: cooled to 0 C
* clarified, filtered and bottled
103
Sparkling winemaking
Bottle fermented
Traditional Method (methode champenoise)
* produce dry base wine
* no SO2 added at end of fermentation
* add liqueur de tirage and yeast
* bottled and sealed (cork or crown seal)
* secondary fermentation to increase 1.2 - 1.3% abv
* autolysis of yeasts to add complexity
* riddled by hand or automatic ridding machines (remuage)
* disgorgement
* add liqueur d'expedition
* sealed by cork and wire cage (muselet)
* further aging
* packing and distribution
* Champagne, Cava, premium sparkling wines
* complex wines, bready, biscuit flavours
Transfer Method
* fermented wine emptied into pressurized tank
* cooled to -5 C
* add dosage (sweetening wine)
* filter to bottle
* slight loss of quality
* mid-market New World sparkling wines
Tank Method (cuve close or Charmat)
* secondary fermentation in sealed pressurised tank
* lees contact
* sweetened, filtered and bottled under pressure
* lower production costs
* German Sekt and Prosecco
* coarser and broader bubbles
Carbonation (Pompe bicyclette)
* chill wine
* bubble carbon dioxide into it
* very infereior method
Asti Method & Methode Ancestrale
* Moscato
* must pumped into a pressure vessel and yeast added
* CO2 allowed to escape to atmosphere
* 5% abv: valves closed to trap CO2
* 6-9% abv and 60-100 g/l sugar: cooled to 0 C
* clarified, filtered and bottled
